1/*
2 * Copyright (c) 1997 - 2000, 2002 Kungliga Tekniska Högskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * 3. Neither the name of the Institute nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#include "krb5_locl.h"
35#include "store-int.h"
36
37typedef struct mem_storage{
38    unsigned char *base;
39    size_t size;
40    unsigned char *ptr;
41}mem_storage;
42
43static ssize_t
44mem_fetch(krb5_storage *sp, void *data, size_t size)
45{
46    mem_storage *s = (mem_storage*)sp->data;
47    if(size > (size_t)(s->base + s->size - s->ptr))
48	size = s->base + s->size - s->ptr;
49    memmove(data, s->ptr, size);
50    sp->seek(sp, size, SEEK_CUR);
51    return size;
52}
53
54static ssize_t
55mem_store(krb5_storage *sp, const void *data, size_t size)
56{
57    mem_storage *s = (mem_storage*)sp->data;
58    if(size > (size_t)(s->base + s->size - s->ptr))
59	size = s->base + s->size - s->ptr;
60    memmove(s->ptr, data, size);
61    sp->seek(sp, size, SEEK_CUR);
62    return size;
63}
64
65static ssize_t
66mem_no_store(krb5_storage *sp, const void *data, size_t size)
67{
68    return -1;
69}
70
71static off_t
72mem_seek(krb5_storage *sp, off_t offset, int whence)
73{
74    mem_storage *s = (mem_storage*)sp->data;
75    switch(whence){
76    case SEEK_SET:
77	if((size_t)offset > s->size)
78	    offset = s->size;
79	if(offset < 0)
80	    offset = 0;
81	s->ptr = s->base + offset;
82	break;
83    case SEEK_CUR:
84	return sp->seek(sp, s->ptr - s->base + offset, SEEK_SET);
85    case SEEK_END:
86	return sp->seek(sp, s->size + offset, SEEK_SET);
87    default:
88	errno = EINVAL;
89	return -1;
90    }
91    return s->ptr - s->base;
92}
93
94static int
95mem_trunc(krb5_storage *sp, off_t offset)
96{
97    mem_storage *s = (mem_storage*)sp->data;
98    /* make SIZE_T_MAX to something that wont turn into -1 */
99    if(offset > (off_t)(SIZE_T_MAX >> 1) || (size_t)offset > s->size)
100	return ERANGE;
101    s->size = (size_t)offset;
102    if ((s->ptr - s->base) > offset)
103	s->ptr = s->base + offset;
104    return 0;
105}
106
107static int
108mem_no_trunc(krb5_storage *sp, off_t offset)
109{
110    return EINVAL;
111}
112
113static void
114mem_free(krb5_storage *sp)
115{
116    mem_storage *s = sp->data;
117    memset(s->base, 0, s->size);
118    free(s->base);
119}
120
121
122/**
123 * Create a fixed size memory storage block
124 *
125 * @return A krb5_storage on success, or NULL on out of memory error.
126 *
127 * @ingroup krb5_storage
128 *
129 * @sa krb5_storage_emem()
130 * @sa krb5_storage_from_readonly_mem()
131 * @sa krb5_storage_from_data()
132 * @sa krb5_storage_from_fd()
133 * @sa krb5_storage_from_mem_copy()
134 */
135
136KRB5_LIB_FUNCTION krb5_storage * KRB5_LIB_CALL
137krb5_storage_from_mem(void *buf, size_t len)
138{
139    krb5_storage *sp = malloc(sizeof(krb5_storage));
140    mem_storage *s;
141    if(sp == NULL)
142	return NULL;
143    s = malloc(sizeof(*s));
144    if(s == NULL) {
145	free(sp);
146	return NULL;
147    }
148    sp->data = s;
149    sp->flags = 0;
150    sp->eof_code = HEIM_ERR_EOF;
151    s->base = buf;
152    s->size = len;
153    s->ptr = buf;
154    sp->fetch = mem_fetch;
155    sp->store = mem_store;
156    sp->seek = mem_seek;
157    sp->trunc = mem_trunc;
158    sp->free = NULL;
159    sp->max_alloc = UINT_MAX/8;
160    return sp;
161}
162
163/**
164 * Create a fixed size memory storage block
165 *
166 * @return A krb5_storage on success, or NULL on out of memory error.
167 *
168 * @ingroup krb5_storage
169 *
170 * @sa krb5_storage_mem()
171 * @sa krb5_storage_from_mem()
172 * @sa krb5_storage_from_readonly_mem()
173 * @sa krb5_storage_from_fd()
174 * @sa krb5_storage_from_mem_copy()
175 */
176
177KRB5_LIB_FUNCTION krb5_storage * KRB5_LIB_CALL
178krb5_storage_from_data(krb5_data *data)
179{
180    return krb5_storage_from_mem(data->data, data->length);
181}
182
183/**
184 * Create a fixed size memory storage block that is read only
185 *
186 * @return A krb5_storage on success, or NULL on out of memory error.
187 *
188 * @ingroup krb5_storage
189 *
190 * @sa krb5_storage_emem()
191 * @sa krb5_storage_from_mem()
192 * @sa krb5_storage_from_data()
193 * @sa krb5_storage_from_fd()
194 * @sa krb5_storage_from_mem_copy()
195 */
196
197KRB5_LIB_FUNCTION krb5_storage * KRB5_LIB_CALL
198krb5_storage_from_readonly_mem(const void *buf, size_t len)
199{
200    krb5_storage *sp = malloc(sizeof(krb5_storage));
201    mem_storage *s;
202    if(sp == NULL)
203	return NULL;
204    s = malloc(sizeof(*s));
205    if(s == NULL) {
206	free(sp);
207	return NULL;
208    }
209    sp->data = s;
210    sp->flags = 0;
211    sp->eof_code = HEIM_ERR_EOF;
212    s->base = rk_UNCONST(buf);
213    s->size = len;
214    s->ptr = rk_UNCONST(buf);
215    sp->fetch = mem_fetch;
216    sp->store = mem_no_store;
217    sp->seek = mem_seek;
218    sp->trunc = mem_no_trunc;
219    sp->free = NULL;
220    sp->max_alloc = UINT_MAX/8;
221    return sp;
222}
223
224/**
225 * Create a copy of a memory and assign it to a storage block
226 *
227 * The input data buffer is copied and the orignal buffer can be freed
228 * during the life the storage.
229 *
230 * @return A krb5_storage on success, or NULL on out of memory error.
231 *
232 * @ingroup krb5_storage
233 *
234 * @sa krb5_storage_emem()
235 * @sa krb5_storage_from_mem()
236 * @sa krb5_storage_from_data()
237 * @sa krb5_storage_from_fd()
238 */
239
240krb5_storage * KRB5_LIB_FUNCTION
241krb5_storage_from_mem_copy(void *buf, size_t len)
242{
243    krb5_storage *sp = malloc(sizeof(krb5_storage));
244    mem_storage *s;
245    if(sp == NULL)
246	return NULL;
247    s = malloc(sizeof(*s));
248    if(s == NULL) {
249	free(sp);
250	return NULL;
251    }
252    sp->data = s;
253    sp->flags = 0;
254    sp->eof_code = HEIM_ERR_EOF;
255    s->base = malloc(len);
256    if (s->base == NULL) {
257	free(sp);
258	free(s);
259	return NULL;
260    }
261    memcpy(s->base, buf, len);
262    s->size = len;
263    s->ptr = s->base;
264    sp->fetch = mem_fetch;
265    sp->store = mem_store;
266    sp->seek = mem_seek;
267    sp->trunc = mem_trunc;
268    sp->free = mem_free;
269    return sp;
270}
271